Catalytic oxidation of ethanol and acetaldehyde over Pd/γ-Al₂O₃-TiO₂catalysts

Pd/γ-Al₂O₃-TiO₂catalysts with 1% palladium loading were prepared by mixed sol-gel and mechanic mixing methods. Their activity for complete oxidation of ethanol and acetaldehyde was tested. The results showed that Pd/γ-Al₂O₃-TiO₂catalyst prepared by mixed sol-gel method is more active than Pd/TiO₂ and Pd/Al₂O₃ separately for simultaneously oxidation of ethanol and acetaldehyde. The conversions of ethanol and acetaldehyde over Pd/γ-Al₂O₃-TiO₂ at 150℃ were 98.9% and 98.5%, respectively; the catalyst also shows a good stability under these conditions. The bulk phase and surface characterizations like XRD, SEM and FT-IR showed that there may be a strong interaction between γ-Al₂O₃ and TiO₂ on Pd/γ-Al₂O₃-TiO₂, which brings on a moderate specific surface area and pore volume. γ-Al₂O₃ may take part in the formation of catalyst surface structure, which may be favorable for the catalytic oxidation of ethanol and acetaldehyde.